In general, a coil spring has been manually manufactured by a skilled hand. However, for this purpose, only primitive equipment such as a shaft sealing or an apparatus for winding a heat-treated coil has been employed, thereby resulting in low productivity and non-uniform products.
Efforts have been unceasingly under way to solve problems associated with the conventional manufacturing method of the coil spring. Against this technologic backdrop, there has been a development of an apparatus for manufacturing the coil spring by winding a coil spring material produced from a furnace around a motor-rotated mandrel.
As shown in FIG. 1, the apparatus for manufacturing the coil spring has a motor 3 installed at one end of a mandrel 4. A driving shaft of the motor 3 rotates the mandrel 4 through a gear 6 inside a gear box 5.
Also, a chuck 7 is formed at the one end of the mandrel 4 to press the one end of the coil spring material 2 toward the mandrel 4 for fixing. A driving means 8 is disposed at the one end of the mandrel 4 to move the chuck 7 vertically with respect to a length direction of the mandrel 4.
The driving means 8 includes a rotating cylinder 8a and a rotating shaft 8b rotating by the rotating cylinder 8a. Here, the rotating shaft 8b is disposed rotatable about the gear box installed in a body.
That is, in the conventional apparatus for manufacturing the coil spring, the motor 3 and the gear 6 are disposed at the one end of the mandrel 4 and the rotating cylinder 8a and the rotating shaft 8b are also disposed at the one end of the mandrel 4.
The apparatus for manufacturing the coil spring as configured above has been improved partially in terms of a manufacturing method over the manual production of the coil spring. But the apparatus as just described also bears limitations due to inability to produce a great number of coil springs. That is, the apparatus for manufacturing the coil spring is configured such that only one coil spring is produced with a coil spring material 2 produced from a furnace, thereby demonstrating ineffective productivity.